It would appear that popular culture wishes to attribute much of sexual behavior in humans to biology. These simplified views rely on a picture of human sexuality that allows for little variation, and concomitantly little variation in sexual and related gender relationships. These deterministic views of sexuality are often supported by reliance on a highly selective set of examples from animal models, and are elaborated by biased interpretations of findings in human research. Arguments are made to seem scientific by the introduction of details about biological mechanisms, especially the endocrine system and its hormones.
In this section we review some of the assumptions implicit in popularized views about a natural sexuality and its biological basis, and present evidence that discredits them. This evidence is organized according to two principal points: (a) There is a wide range of variation in animal bonding, mating, fertilization, and gestation that contradicts the direct-drive model linking hormones and behavior, and (b) there often is bidirectional influence between behavior and hormones including environmental factors, such as the social and cultural context of behavior and biology. The following discussion highlights variation across a range of species and is designed to provide a framework for rebutting a cavalier reliance on scientific explanations for sexuality.